Whenever I talk about the search for life in the Universe and its emphasis on water, I get comments that scientists aren’t being creative enough. Couldn’t there be lifeforms which are completely different from life on Earth? Astrobiologists have only scratched the surface in their search for life in the Universe, and they’re going after the low-hanging fruit. Since life on Earth can be found wherever there’s water, why not check out the water on other worlds? But it’s possible there are aliens living right here on Earth among us, in a shadow biosphere, we just haven’t detected them yet.